SPR Biosensor Based on Polymer Multi-Mode Optical Waveguide and Nanoparticle Signal Enhancement.

Johanna-Gabriela Walter,Kort Bremer,Bernhard Wilhelm Roth,Lourdes Shanika Malindi Alwis,Alina Eilers

doi:10.3390/s20102889

Abstract

We present a surface plasmon resonance (SPR) biosensor that is based on a planar-optical multi-mode (MM) polymer waveguide structure applied for the detection of biomolecules in the lower nano-molar (nM) range. The basic sensor shows a sensitivity of 608.6 nm/RIU when exposed to refractive index changes with a measurement resolution of 4.3 × 10−3 RIU. By combining the SPR sensor with an aptamer-functionalized, gold-nanoparticle (AuNP)-enhanced sandwich assay, the detection of C-reactive protein (CRP) in a buffer solution was achieved with a response of 0.118 nm/nM. Due to the multi-mode polymer waveguide structure and the simple concept, the reported biosensor is well suited for low-cost disposable lab-on-a-chip applications and can be used with rather simple and economic devices. In particular, the sensor offers the potential for fast and multiplexed detection of several biomarkers on a single integrated platform.

Highlights

The detection of biomarkers in body fluids plays a vital role in early diagnosis and treatment of diseases
Since optical glass fibers were applied for the purpose of coupling light in and out of the waveguide, their positions relative to the planar-optical waveguide structure are sensitive to external perturbations, i.e., temperature variations or vibrations
A surface plasmon resonance (SPR) biosensor based on a planar-optical MM polymer waveguide for the detection of biomolecules in the lower nM range was successfully developed

Summary

Introduction

The detection of biomarkers in body fluids plays a vital role in early diagnosis and treatment of diseases. The potential of biomarkers for the said purpose is not explored to its full capacity due to limitations in the current sensing technologies [1]. This results from the fact that biomarkers are often present at very low concentrations in combination with other proteins, making their identification a strenuous task. Current methods of detection include enzyme-linked immunosorbent assays (ELISA), surface plasmon resonance (SPR) spectroscopy, surface enhanced. SPR presents the most advanced label-free and real-time biomarker detection capability [9,10,11,12,13]. The ability of SPR to monitor the interaction between a molecule immobilized on the surface of the sensor and the molecular partner in a solution has rendered it a powerful tool for biomolecular interaction analysis [14]

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Discussion

Conclusion